Door operating mechanism



July 20, 1965 s. BERRY ETAL DOOR OPERATING MECHANISM Filed March 13.1961 4 Sheets-Sheet 1 INVENTORS GAE/VN 55x2) camuis r. 8R/6'GS, it.

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7 3411? A rfo P117573 July 20, 1965 G. BERRY ETl'AL 3,195,617

DOOR OPERATING MECHANISM Filed March 13. 1961 4 Sheets-Sheet 4 UnitedStates Patent 3,195,617 D0611 @YERATWG MEQHANESM Glenn Berry,Birmingham, Qharles T. Briggs, in, and Qlarcnce F. Treppa, Royal Gait,and Edson L. Barlow, in, Rochester, Mich, asslgnors, by direct andrhesus assignments, to The Stanley Works, New Eritain, Conn, acorporation of Connecticut Filed lvlar. 1'5, M61, Ser. No. 95,3691tliaims, (Cl. loll-193) This invention relates generally to dooroperating mechanisms, and more particularly to radio controlled dooroperating mechanisms for overhead type doors.

Electrically powered door operating mechanisms are known in the art foropening and closing overhead type doors such as those commonly used ingarages and buildings wherein the door is supported on tracks for move-=room between a vertical closed position and a horizontal open position.Radio controls for remotely controlling the operation of electricallypowered door operating mechanisms are also known and commerciallyavailable. However, the complexity of known mechanisms and the addedcost of manufacture, installation and service resulting therefrom remainas an obstacle to supplying the potential mass market for such devices.

It is therefore an object or" the present in ention to provide animproved door operating mechanism which is economical to manufacture andinstall.

Another object is to provide an electrically powered and radiocontrolled door operator for overhead type doors which is easilyassembled and installed by relatively unskilled labor, and when onceinstalled is still economical to service.

A further object is to provide a door operator which utilizes the knownsystem of a carriage, track and heiriole roller chain drive therefor,but which provides these elements in an improved form which togethercontribute to the economy of the door operator while overcoming severaldisadvantages of the prior art systems.

Another obiect of the present invention is to provide an improved termof limit switch mechanism which is easily and accurately adjustable forstopping travel of the door at the extremes of travel thereof.

In the accompanying drawings:

FIG. 1 is a perspective elevational view of a door operator constructedin accordance with the present invention and installed for use with aconventional sectional overhead garage door;

FIG. 2 is a cross sectional View taken on line Z--2 of FIG. 1illustrating the track and carriage of the door operator;

FIG. 3 is a top view taken in horizontal section on the line 3-3 of FIG.1 illustrating the shock mounted chain idler sheave at the front end ofthe track;

P16. 4 is a front elevational view of the radio receivermotor controlunit of the door operator taken in vertical section through the track online ll of FIG. 1;

FIG. 5 is a fragmentary cross sectional top view taken on the line 5-5of FIG. 4 illustrating a portion of the limit switch mechanism of theinvention;

FIG. 6 is a fragmentary elevational view illustrating the electricmotor, driving mechanism and radio receivermotor control unit of thedoor operator;

FIGS. 7 and 8 are bottom and top views respectively of the radioreceivermotor control unit taken respectively on the lines '7-7 and 3-8of PK} .6;

FIG. 9 is an end view taken partially in section on the line 9-9 of P16.6 illustrating the suspension of the motor from the track;

. FIG. 10 is a fragmentary sectional view taken on the Fatented July 29,1965 line ill-ll} of FIG. 6 illustrating the suspension of the controlunit housing from the track;

FIG. 11 is a fragmentary elevational view of a modified form of clutchmechanism taken in section on the line l1ll of FIG. 12;

FIG. 12 is a fragmentary bottom plan view of the modified clutchmechanism taken in section on the line l2ll2 of FIG. 11;

FEG. i3 is a fragmentary top plan view of a modified limit switchactuating mechanism taken in section on line 13-13 of MG. 14-; and

PEG. 14 is a side elcvational view of the modified form of limit switchactuating mechanism partially broken away to illustrate details.

Referring to FIG. 1 in the accompanying drawings, the door operator ofthe present invention is shown completely assembled and installed foruse with a conventional sectional overhead garage door lit which issupported along the side edges thereof by rollers 12 which run in a pairof guide tracks to, only one of which is shown inasmuch as constructionand operation of this type of door is well understood in the art.Generally speaking, the door operator of the present invention includesa tubular track it; supported at the front end thereof by a channel l3which is bolted to the header beam of the garage above the top center ofthe door opening. Track to is supported near the other end thereof by aslidably adjustable hanger strap 29 bolted to the ceiling of the garageor to any convenient and suitable structural member thereof. A combinedradio receiver-motor control unit 22 is suspended from traclr lorearwardly of hanger strap Zia for controlling electrical power to anelectric motor 24- also suspended from track 16 adjacent unit 22. Motor2 is connected in driving relation with a vertical spindle as which isjournalled for rotation within a bracket 34 mounted adjacent the frontof unit 22. The upper end of spindle 68 drives a sprocket around whichis trained a flexible element adapted to run longitudinally within trackto for propelling a carriage block 36 therein, which carriage in turn isconnected via a linkage arm 38 to the inner side of door till so thatmovement of carriage 36 raises and lowers door Illi.

Referring to FEGS. 2 and 3, track l6 comprises a tubular memberpreferably formed into a rectangular cross section having a bottom wallwhich is open at the center thereof throughout the length of the track.The bottom Wall consists of a pair of horizontal bottom wall portions16a and 16b extending inwardly from the side walls of track 16, theinner ends of which are bent upwardly to form a pair of vertical flanges16c and led which define the longitudinal opening or slot 4%thercbetween. A carriage 36, preferably comprising a generallyrectangular block of nylon, is shaped to be received closely withintubular track to so as to slide along bottom wall portions 16a, 16bthereof while being guided for longitudinal movement in the track by thesurrounding walls of the track. The bottom surface of carriage block 36is provided with a longitudinal groove 36a which fits over the uprightflanges rec, 16d of the track bottom wall. An inverted U-shapedconnecting link 42, is riveted to carriage block as at the center ofgroove 36a, and the linkage arm 33 is pivotably connected thereto by asuitable fastener 44.

A flexible driving element 42-6 preferably comprising a roller chainruns entirely within track 16 and is utilized for driving carriage blockas therein. Carriage block as is provided with a pair of laterallyspaced and parallel passages or bores Sol) and 36c which extendlongitudinally therethrough for receiving the running portions of chain46. The end links of chain as are received in bore 36c and are eachfastened to carriage block 36 by a connecting pin 48 which is receivedin a vertical hole drilled in the upper surface of block 36 so as tointersect the axis of bore 360. v

The forward end of chain 46 (FIG. 3) is trained around an idler sheave50 preferably comprising a nylon spool which is journalled by an axlebolt 51 between the sides of a U-shaped sheave carriage 52 which isslidably received within tubular track 16. A headed bolt 54 extendsthrough the end wall of sheave carriage 52 and then through the end wallof a U sh-aped bracket 55 which is necked down for insertion into theforward end of tubular track 16. Bolt 54 receives a nut 58 on thethreaded end thereof which holds a retaining washer 60 against one endof a coil compression'spring 62, the other end of which bears againstthe wall of U-shaped bracket 56. This spring connection of sheavecarriage S2 with the end of the track 16 provides a shock mounting ofidler sheave 50 which compensates for starting and stopping stresses inthe door operator by permitting the sheave to float longitudinally intrack 16, spring 62 also serving to maintain chain 46 constantly intension. Bracket 56 also supports the forward end of tubular track 16 onthe upper end of mounting channel 18, a pivotable connection beingprovided therebetween by a carriage bolt 64 or other suitable fasteningmeans.

Referring to FIG. 4, the other end of flexible roller chain 46 istrained around a toothed driving sprocket 66 which is affixed to theupper end of a driving spindle 68. A pair of vertical side plates 34aand 34]) are fastened by suitable fasteners to the sides of tubulartrack 16 and are joined at the bottom edges thereof to a cross plate 70to form bracket -34 for supporting drive spindle 68, An invertedU-shaped upper cross plate 72 is welded to the inner sides of plates34a, 34b so as to extend therebetween adjacent the bottom wall of track16. Upper cross plate 72 supports a flanged bearing 74 which in turnsupports a'spacer collar 76 on which sprocket 66 rotates and rests.Another flanged bearing 78 is supported by bottom plate 70 so as toprovide the lower journal for spindle A large spoked pulley 80 isrotatably journalled on spindle 68 near the lower end thereof forrotation by a V-belt 82 trained therearound. Power is transmitted frompulley 80 to spindle 68 via a friction clutch mechanism which includes acircular disc 84, made of suitable friction material, which is fastenedto the spokes of pulley 80. A clutch plate 86 and a hexagonal nut 88integral therewith are center tapped to be threadably received on thelower endof spindle 68 and are keyed thereto by a cotter pin 90. Ahelical compression spring 92 fits loosely around spindle 68 betweenplate 70 and the upper face of the hub of pulley 80, spring 92 providinga downward force cumulative to the weight of pulley 80 to maintainclutch disc 84 in frictional engagement with the upper surface of clutchplate 86.

As shownin FIGS. 6 and 9 electric motor '24 is suspended from the end oftrack 16 by a U-shaped bracket 94 which is bolted to the sides of thetrack and which has a circular mounting plate 96 Welded to the bottomthereof to which motor 24 is bolted. The drive shaft 98 of motor 24 hasa small driving pulley 100 aflixed thereto around which V-belt 82 istrained so as to provide with larger pulley 80 a speed reduction drivefor spindle 68. Motor 24 is preferably a conventional permanent splitcapacitor motor designed to be instantly reversible while at rest orrunning under intermittent duty conditions.

The radio receiver-motor control unit 22 (-FIGS. 4, 6, 7 and 8) ismounted in a housing 102 which contains all the components 104 of aradio receiver as well as all the control components for motor 24.Preferably the radio receiver is one designed particularly forgaragedoor controls, such as the ModelRCZB receiver sold by ll/lulti-Products Co., of Oak Park, Michigan. This receiver uses asuperheterodyne circuit which may be pow- 4- ered by standard housecur-rent and which is designed to operate a bi-stable relay upon receiptof a suitable signal from a vehicle-mounted transmitter, not shownherein inasmuch as the structure and operation of such equipment is wellunderstood in the art.

In accordance with one feature of the present invention, the components104 of the above radio receiver are mounted in housing 102 along withconventional motor control components including a capacitor for motor24, a transformer 112, a circuit breaker 114, a bi-stable relay 116, alimit switch 118 and a socket 120 for an illuminating lamp.The:foregoing components are compactly arranged by mounting a circuitboard 106 with components 104 supported thereon across a pair of chassisside plates 122 which are fastened to the front wall section of athree-sided sheet metal stamping 102a of housing 102. Transformer 112 isattached to the outer side of one of side plates 122 and the motorcontrol components are supported from the front wall section of stamping102a Within the confines of chasis side plates 122. Housing 102 alsoincludes top and bottom cover stampings 102k and 102s which fit over thetop and bottom edges of three-sided member 102a and are attached bymetal screws thereto. Housing 102 is completed by a rear cover stamping102d which is independently removable for access to the radio receivercomponents 104.

As shown in FIG. 10, the top cover 10% of housing 102 has a'U-shapedbracket 124 Welded to the center thereof which is adapted to fit aroundthe bottom and sidesof tubular track 16 and which is attached thereto bymetal screws to support housing 102 in a compact arrangement betweenmotor 24 and spindle bracket 34. Sufiicient clearance is providedbetween the bottom cover 1020 and pulley 80 (FIG. 6) so that housing 102may be removed by disconnecting bracket 124 from track 16, lowering thehousing until bracket 12 4 clears track 16, and then withdrawing thehousing sideways from between motor 24 and bracket 34. To facilitatesuch removal, a socket 126 is provided in the wall of housing 102 sothat motor 24 may be electrically connected to the output terminals ofrelay 116 by plugging a power cord 128 into socket 126. g

The control circuits are conventional, limit switch118 comprising abi-stable single pole-double throw switch which is connected in serieswith the radio controlled relay switch 116 (a double pole-double throwbi-stable relay) between an input power lead 130 and motor lead 128 forcontrolling operation of motor 24., Provision is also made for manualpushbutton control of motor 24 via leads 132 which are connected viaterminal strip 134 to leads which shunt the radio controlled relayswitch- 116. v In accordance with another feature of the invention, alimit switch mechanism (FIGS. 4 and 5) is provided wherein switch 118 ismounted against the front wall of stamping 102a at the center thereofwhere a hole 136' is provided through which an operating arm 138 ofswitch 118 extends horizontally so as to terminate adjacent spin dle 68.The portion of spindle 68 extending between bearings 74 and 78 isthreaded so as to form a lead screw for threadably receiving a pair oflimit switch actuating nuts 140 and 142. Preferably nuts 140, 142 aremade of nylon and are square shaped so as to be non-rotatably guided foraxial travel on spindle 68 by a U-shaped guide 144 (FIG. 5). Guide 144is pivotably mounted at its upper end on a pin 146 supported by plates34a, 34b. Guide 144 is held in the vertical closed position thereof by acotter pin 148 supported by plates 34a. 34b so as to extend across thelower portion of the outer face of guide 144. A tab 150 is formed bybending a portion of this face outwardly at right angles thereto, tab150 having a width slightly larger than opening 40 in the bottom wall oftrack 16. Thus guide 144 may be pivotably raised out of engagment withthe nuts140, 142 -by removing cotter pin 148 and swinging guide 144upwardly to a horizontal position where it may be temporarily held by apress fit of tab 150 between bottom wall flanges 16c, 16d of track 16.This feature permits quick access to and rotation of nuts 14% and 142 inorder to adjust them axially on spindle 68.

The electrical operation of the improved door operating mechanism of theinventiondescribed above is generally similar to known radio controlleddoor operators, the improvements of the invention being primarily in themechanical structure and arrangement of the mechanism to provide anefiicient and economical door operator without sacrificing reliability.Briefly, a radio transmitter is used to generate a signal to which theradio receiver of control unit 22 is tuned, this transmitted sig nalcausing the receiver to provide an output signal which actuatesbi-stable relay 116 which thereupon connects the power circuit to motor24 so that it is energized for driving chain 45 via pulley 100, belt 82,pulley as, spindle 6S and sprocket 6%. Assuming door to is closed, therunning portion of chain 46 connected to carriage block 36 pulls thecarriage from the position thereof shown in FIG. 1 slidably along track16 rearwardly towards driving sprocket 66. This motion is transmittedvia link 38 to the top section of door it) so that the door is raised toits horizontal open position on guide tracks 14. During this travel ofchain 4%, nut 14% travels axially downward on the threads of spindle 63until nut 14% engages limit switch operating arm 13%, thereby actuatinglimit switch 118 to cut off power to motor 24. Receipt of another signal(or operating a pushbutton switch connected to leads 132) reverses thesequence by causing reverse rotation of motor 24, the reverse rotationof spindle 68 causing chain 46 to pull carriage 36 forwardly along trackis to thereby lower door 19. During this reverse rotation of spindle 6Snut 142 travels upwardly until it engages arm 138 to stop the motor.Hence the axial spacing between nuts 142 determines the distance whichcarriage 36 travels in track 16, and the axial positions of nuts 14% and142 respectively determine the desired extremities of travelcorresponding to the open and closed positions of door 10.

The above described door operating mechanism i economical tomanufacture, install and service. The rectangular tubular track 16provides a light weight and high strength beam which may be readilypressed or rolled from a single sheet of metal. Many of the othercomponents are items which are adapted for manufacture by low coststamping operations. The installation requires that only two supportingmembers, channel 18 and hanger strap- 21?, be attached to the garage.Once channel 13 is bolted to t e garage header, the remainder of thedoor operator (which may be readily assembled while on the ground frommajor sub-assemblies) is raised into place by inserting the forward endof track to into the upper end of channel 13 and then inserting bolt 64to provide the pivotable connection therebetween. Then the rear of theunit is raised and connected to the clamp provided at the bottom end ofhanger strap 26'.

The suspension of motor 2 radio receiver-motor control unit 22 anddriving spindle (28 all beneath track 16 provides a door operator whichrequires a minimum of space for installation, particularly with regardto the head room required between the door operator and the ceiling.Track 16 serves as a mounting beam for all the parts as well as theguide track for the carriage 36. Moreover, track 16 provides a housingfor completely enclosing the moving chain t6. Bores 36b and 36c incarriage block 36 assist in guiding the running portions of chain 426intermediate the ends of track 16 so that they are maintained directlyabove the bottom wall portions 1dr! and ldb which comprise the tracks ofthe tubular track 15, thereby insuring that grease or oil drippage fromthe chain is collected in these trough-like tracks rather than fallingon the occupants or contents of the building therebelow. If the chainshould break it likewise will be caught by the tracks. The oil drippagefrom chain 46 onto the bottom wall portions 16a, 165 provides continuouslubrication of these track surfaces so that the carriage block slidesfreely thereon, The use of a nylon carriage block also contributes to alow friction drive.

The use of spindle as as a lead screw for the traveling nuts Mil, 142permits the limit switch to be mounted with the other electricalapparatus within housing 102 of the control unit 22. Hence, all of thiselectrical apparatus is quickly removable in the event of a malfunctionoccurring in the electrical system, and the entire control unit 22 maybe immediately replaced with a new or rebuilt unit so that no unduedelays are experienced by the user of the door operator and so that theskilled maintenance work may be more conveniently and reliably done at aervice center.

A modified form of clutch mechanism is shown in FIGS. 11 and 12 whereinelements identical to those of the clutch mechanism shown in FIG. 4 havebeen given like reference numerals and the description thereof notrepeated. The specific clutch mechanisms disclosed herein form no partof the present invention and are disclosed merely for the purposes ofillustrating preferred forms of clutches well adapted for use in thedoor operating mechanism oi the present invention. Reference may be hadto a copending' application entitled Drive Mechanism, Ser. No. 182,391,filed on March 26, 1962, by Glenn Berry and Clarence F. Treppa whereinsuch clutch mechanisms are disclosed and claimed. The upper clutch platecomprises the circular disc 34, preferably made of cork, and a circularmetal disc cemented thereto, disc ltl having three U-shaped bracket 162spot welded to the upper surface thereof at 120 intervals (FIG, 12) soas to each receive a spoke 89a of pulley 8-13 therein. A modified lowerclutch plate 164 is vprovided which comprises a circular metal dischaving a threaded center hole and four smaller holes 165 spaced at 90intervals radially outward from the center hole of the disc. Spindle asis also modified by forming a pair of oppositely disposed fiat surfiaces166 which extend axially upward from the bottom end of the spindle. Thecircular portions of the periphery of spindle 68 intermediate fiatsurfaces ins are provided with an external interrupted thread 1163 forthreadably receiving clutch plate ll ton the spindle.

Spindle as also receives a U-shaped bracket 1'70 having a flat sidedcenter hole 172 in the horizontal center portion thereof which iscomplemental to the lower, flat sided portion of spindle 68 so as to beaxially slidable along flat surfaces 165 While being held againstrotation relative to the spindle. A pair of studs 1'74 are secured tothe center portion of bracket 17% so as to project upwardly therefrom inali nment with a pair of diametrically opposite holes 165 in clutchplate 164. A push not 1% is detachably secured to the bottom end ofspindle 6% for supporting a helical compression spring 178 wound looselyaround spindle 68 for resiliently urging bracket lili upw andly againstclutch plate 164. The lower ends 1534 of the arm portions of bracket 17%are reversely bent to provide a pair of finger grips for pulling bracket1'70 downwardly along spindle as to withdraw studs lli' lfrom holes 165of the clutch plate.

With the above modified form of friction clutch mechanism it is a simplematter to adjust the clutch plate ongagement pressure developed byclutch spring 92. Bracket 17% is merely pulled downwardly on spring 178until studs 174 are disengaged from clutch plate 164, and then clutchplate 164* is rotated on the spindle threads 168 until it is in thedesired axial position on the spindle. For example, to increase .themaximum torque transmitted by the clutch, clutch plate 164 is threadedupwardly on spindle res so as to further corn press clutch spring 92. Itis to be understood that pulley 80 and upper clutch plate 160 havesmooth bores 50 as to be journalled on spindle 68 for rotation relativethereto and thus are free to move axially with clutch plate 164. Oncethe desired clutch tension is obtained, bracket 170 is releasedwhereupon it is urged upwardly by spring 178 into engagement with clutchplate 164. If bracket 170 is inadvertently left disengaged (with studs174 out of registry with holes 165), the first 90 degrees of rotation ofclutch plate 164 will bring these holes and studs into registrywhereupon spring 178 automatically drives bracket 176 into properengagement with the clutch plate so that it is held against rotationrelative to spindle 68. g

A modified switch actuating mechanism is shown in FIGS. 13 and 14. Inorder to protect the operating arm 138 of limit switch 118 duringshipment or handling of the control unit 22, the front face of stamping102a of housing 102 is provided with a vertically extend-ing recess 182on which switch 118 is mounted. An opening 184 is formed in recessedportion 182 through which arm 16-8 extends, arm' 18*8 terminating flushwith the plane of the front face of stamping 102a. A pair of circularactuating nuts 186 are threadably received on spindle 68, each nut 186having four radial arms 188 extending from the periphery thereof at 90intervals adapted to rot-ate into recess 182 to overlap the end ofswitch arm 1 38, actuating nuts 1'86 functioning in the same manner asthe previously described actuating nuts 140, 142. The parallel verticalsides of arms 188 of nuts 186 are spaced apart to fit s-lidably within aU-shaped guide- 190. Guide 190 is supported on .a door 192 in a verticalposition so as to receive the nut arm 188 spaced 90 from the nut armwhich is aligned with switch arm 138. Door 192 has three integral bentarms 1'94 extending from one vertical edge thereof which are received insuitable slots 196 of a U-sh-aped spindle supporting bracket 198. Hencedoor 192 may be opened by swinging it about a vertical axis on hingearms 1:94, thereby disengaging guide 190 from actuating nuts 186 topermit axial adjustment ofthese nuts. Door 192 is held in the closedposit-ion by suitable spring clips 200 adapted to secure the top andbottom edges of door 192 to the corresponding edges of the door openingin spindle bracket 198, It will be seen that the above modified limitswitch actuating mechanism retains the advantages of the previouslydescribed embodiment while permitting a flush mounting of the limitswitch operating arm 130. V

We claim:

1. In a door operator the combination comprising a track having acarriage supported thereon for movement lengthwise thereof, an electricmotor supported on said track adjacent one side thereof and having arotor drive shaft disposed perpendicular to said track, a housing, aradio receiver-motor control unit protectively enclosed in and solelysupported by said housing, detachable fastener means removablysupporting said housing on said one side of said track adjacent saidmotor, bracket means secured to said track and extending from said oneside thereof adjacent said housing, a threaded spindle journalled insaid bracket means adjacent one face of said housing and parallel tosaid motor shaft, one end of said spindle being disposed within saidtrack, means drivingly connecting said one end of said spindle with saidcarriage for moving said carniage along said track in response tospindle rotation, the other end of said spindle extending beyond saidhousing, means drivingly interconnecting said other end of said spindlewith said motor shaft for rotating said spindle in response to motorrotation, a pair of spaced nuts threadably received on said spindle innon- V rotatable sliding engagement with said bracket means for travelalong said housing face in response. to spindle rotation, said controlunit including a limit switch and means electrically connecting saidswitch to said motor comprising connector means disconnectableexternally of the housing,

said switch having a movable switch actuating o 0 arm extending fromsaid one face of said housing into the space between said nuts such thatsaid nuts alternately engage said arm to operate said switch at thedesired opposite extremes of travel of the door.

2. The combinationset forth in claim 1 wherein said bracket meansincludes a guide member supported thereon for movement between a firstposition wherein said member is disposed parallel to said spindle and insliding engagement with said nuts to prevent rotation thereof relativeto said bracket means and a second position wherein said guide member isdisengaged from said nuts so that said nuts maybe rotated to adjust theaxial position thereof relative to said switch arm. v

3. The combination set forth in claim 1 wherein said bnacket meanscomprises a pair of spaced side plates extending parallel to saidspindleon opposite sides thereof and a pair of spaced spindle journal platesextending transversely of said spindle and secured to said side plates,said plates forming with'said one face of said housing an enclosure forsaid nuts. p

4. In an operating mechanism for actuating an overhead door betweenvertical closed and horizontal'open positions, a tubular beam, means forsupporting said beam in a generally horizontal posit-ion above the openposition of the door and extending in the direction of horizontal travelof the door, said beam having a bottom wall constituting the lowermostportion thereof and comprising a pair of laterally spaced andlongitudinally extending imperforate track surfaces each having'uprightouter and inner reinforcing edges, said inner edges being spaced fromone another to define a longitudinally extending opening therebetween, adrive mechanism sup ported bysaid tubular member near one end thereofincluding an upright spindle extending through said bottom wall opening,a sprocket mounted on the upper end of said spindle for rotationtherewith within said tubular member, idler means supported within saidtubular member near the other end thereof for rotation about an axisparallel to said spindle, a flexible element trained around saidsprocket and idler means and running therebetween within said tubularmember in the form of a pair of runs spaced horizontally apart anddisposed in overlying relation to said track surfaces, one of said runsbeing disposed over one of said track surfaces and the other of saidruns over the other of said track surfaces, a carriage received withinsaid tubular member and supported for movement lengthwise therein onsaid track surfaces, said carriage being connected to one of said runsof said flexible element for movement therewith, said carriage beingadapted to slidably support the other run of said flexibleelement'sp-aced above the track surface disposed therebelow, andmeansconnected to said carriage and extending downwardly through said openingin said tubular member for connecting the carriage with the door forraising and lowering the door in response to movement of said carriagein said tubular member.

5. In a door operator the combination comprising a track having acarriage supported thereon for movement lengthwise thereof and adaptedto be connected to the door for opening and closing the door by saidlengthwise movement, drive means supported on said track including anelectric motor and a drive train operably interconnecting said motorwith said carriage, a housing having a radio receiver-motor control'unitmounted therein, means removably supporting said housing on said track,said drive tnain including a threaded shaft, means journalling saidshaft for rotation adjacent one face of said housing such that saidshaft extends along said one face, a pair of nuts threadably received onsaid shaft in spaced relation from each other, mean-s adjacent saidshaft slidably engaging said nuts to prevent rotation thereof so -thatsaid nuts tnavel adjacent said housing face in response to rotation ofsaid shaft, a limit switch mounted on said housing having a movable armfor actuating said switch extending from said one face of said housinginto the space between 9 said nuts, the travel of said nuts beingcorrelated with the movement of said carriage such that said nutsalternately engage said arm to operate said switch 'at the desiredopposite extremes of travel of the door, and means operablyinterconnecting said switch and motor for deenerg-izing said motor inresponse to operation of said switch by said traveling nuts.

References fited by the Examiner UNITED STATES PATENTS 2,695,781 11/ 54Wark. 2,736,553 2/56 Brown 268-59 1% 2,753,179 7/ S6 Hahn. 2,957,521 10/60 Greeg-or 160-133 FOREIGN PATENTS 467,7 82 6/37 Great Britain.

HARRISON R. MOSELEY, Primary Examiner.

LAWRENCE CHARLES, Examiner.

1. IN A DOOR OPERATOR THE COMBINATION COMPRISING A TRACK HAVING ACARRIAGE SUPPORTED THEREON FOR MOVEMENT LENGTHWISE THEREOF, AN ELECTRICMOTOR SUPPORTED ON SAID TRACK ADJACENT ONE SIDE THEREOF AND HAVING AROTOR DRIVE SHAFT DISPOSED PERPENDICULAR TO SAID TRACK, A HOUSING, ARADIO RECEIVER-MOTOR CONTROL UNIT PROTECTIVELY ENLOSED IN AND SOLELYSUPPORTED BY SAID HOUSING, DETACHABLE FASTENER MEANS REMOVABLYSUPPORTING SAID HOUSING ON SAID ONE SIDE OF SAID TRACK ADJACENT SAIDMOTOR, BRACKET MEANS SECURED TO SAID TRACK AND EXTENDING FROM SAID ONESIDE THEREOF ADJACENT SAID HOUSING, A THREADED SPINDLE JOURNALLED INSAID BRACET MEANS ADJACENT ONE FACE OF SAID HOUSING AND PARALLEL TO SAIDMOTOR SHAFT, ONE END OF SAID SPINDLE BEING DISPOSED WITHIN SAID TRACK,MEANS DRIVINGLY CONNECTING SAID ONE END OF SAID SPINDLE WITH SAIDCARRIAGE FOR MOVING SAID CARRIAGE ALONG SAID TRACK IN RESPONSE TOSPINDLE ROTATION, THE OTHER END OF SAID SPINDLE EXTENDING BE-